Climate change is widely viewed as one of the long-term events most threatening to the Earth and human life. Research shows that since the Industrial Revolution in the 1700s, changes in the Earth’s climate are due in part to human activity — specifically, the burning of fossil fuels and the emission of greenhouse gas.

Fossil fuels have another drawback, in addition to their contribution to climate change: they are finite energy sources. Sooner or later, renewable fuel sources will be needed to sustain the current trajectory of global energy consumption. Renewables continue to be chosen by businesses and individuals over conventional sources.

Based on 24/7 Wall St. analysis of data from the Energy Information Administration, Vermont leads the nation with 99.8% of electricity production accounted for by renewable sources. Delaware produces the least renewable energy as a percentage of its total electricity generation, at just 1.7%.

States have plenty of renewable energy options to choose from. Hydroelectric dams are the largest renewable source in 22 states; wind turbines generate the largest share of renewable energy in 16 states.

Solar panels are a popular option for individuals, families, and small businesses. Compared to wind and hydroelectric, which must rely largely on mechanical improvements to produce more electricity, solar is often touted as having the greatest untapped potential. According to research organization Bloomberg New Energy Finance, solar will become more cost-effective than coal by 2025.

To identify the states using the most renewable energy, 24/7 Wall St. reviewed the percentage of electricity generated by renewable energy sources in each state in 2015. Renewable energy sources are defined as geothermal, conventional hydroelectric, solar, biomass, wind, and wood and wood derived fuels. All data came from the U.S. Energy Information Administration (EIA).